Soften butter to room temperature while preheating oven to 350 degrees F. Mix the cheese spread into the butter and stir in mayonnaise. Add garlic powder and stir unti all is completely blended - no lumps. Gently stir in crabmeat.
Slice the muffins in half and divide the crab mixture on the 12 halves. Cut each half into quarters and place them on baking sheet.
Bake in the oven until the cheese is bubbly and the edges are brown. Serve at once.